Researchers have uncovered a malware-based espionage campaign that subjects Mac users to the same techniques that have been used for years to surreptitiously siphon confidential data out of Windows machines.

In December 1998, a U.S.-based hacker group called Legions of the Underground declared cyberwar on Iraq and China and prepared to protest human rights abuses in those countries by disrupting their Internet access.

Experts from across the security industry collaborated this week to quarantine more than 110,000 Microsoft Windows PCs that were infected with the Khelios worm, a contagion that forces infected PCs to blast out junk email advertising rogue Internet pharmacies.

A new Mac backdoor exploiting CVE-2011-3544 (a Java vulnerability) is being reported. The backdoor appears to be connected to GhostNet. The malware is being used in targeted attacks against non-governmental organizations (NGO).